The principle of an axial flux motor is known from European patent application published under publication number EP 2 607 291 A1. Axial flux motors have proven to be a space-saving construction and especially well suited for use in elevator hoisting machines.
An axial flux motor that is to be used in an elevator hoisting machine needs to have a sufficiently robust bearing between the rotor and the stator. Even though the bearing may normally be replaceable with the apparatus and the method described in Finnish patent application FI 20080544 laid open 2010 Mar. 31, for example, it may still happen that the bearing gets broken before its scheduled maintenance. Other bearing block covers are known from U.S. Pat. No. 6,183,136 B1 and patent applications US 2005/018935 A1, DE 198 39 640 A1 and DE 103 13 273 A1.
When a bearing breaks, lubrication may escape from the bearing. Bearing lubrication entering movable parts of a machine is generally undesired. In the context of hoisting machines and elevators this may at least in theory be dangerous, since a hoisting machine normally comprises a number of brakes engaging a rotatable part of the axial flux motor. Lubrication on such a rotatable could easily make the brakes to slip.
The fitting of the bearing in an axial flux motor as disclosed in FI 020080544 has been realized by means of a recess machined in the rotor. In mechanical engineering, manufacturing tolerances of motor parts may be a significant cost factor. A larger manufacturing tolerance of the bearing causes also a the larger the risk of lubrication leaking from the bearing.